Agroforestry systems are believed to provide various ecosystem services, but evidence supporting these benefits has been limited until recently. This special issue presents recent findings on the ecosystem services and environmental benefits of agroforestry. The paper examines four major ecosystem services and environmental benefits: carbon sequestration, biodiversity conservation, soil enrichment, and air and water quality. Evidence shows that agroforestry, as part of a multifunctional working landscape, can be a viable land-use option that alleviates poverty and provides ecosystem services and environmental benefits. The introduction highlights that agroforestry is increasingly viewed as providing ecosystem services, environmental benefits, and economic commodities. The Millennium Ecosystem Assessment and the International Assessment of Agricultural Science and Technology for Development emphasize the multifunctional role of agroecosystems. There is also interest in providing financial benefits to landowners and farmers for land-use practices that maintain environmental services. Attempts have been made to quantify environmental benefits of agroforestry, but comprehensive reviews are rare. Reviews have mostly focused on a single ecosystem service. For example, Schroth et al. (2004) synthesized the role of agroforestry systems in conserving biodiversity in tropical landscapes. Schroth and Sinclair (2003) addressed soil fertility enhancement by agroforestry practices. Montagnini (2006) focused on carbon sequestration potential of agroforestry systems. The objective of this special issue is to bring together original research articles on various ecosystem services and environmental benefits from agroforestry practices worldwide. The integration of trees, agricultural crops, and/or animals into agroforestry systems can enhance soil fertility, reduce erosion, improve water quality, enhance biodiversity, increase aesthetics, and sequester carbon. These services occur over various spatial and temporal scales. Although the clean development mechanism offers promise for economic returns for carbon sequestration benefits, society's willingness to pay for other ecosystem services is yet to be fully explored. The major ecosystem services of agroforestry are classified into four categories: carbon sequestration, soil enrichment, biodiversity conservation, and air and water quality. Each is discussed in the following sections. Overall, the discussion cuts across the four major categories of ecosystem services identified by the Millennium Ecosystem Assessment.Agroforestry systems are believed to provide various ecosystem services, but evidence supporting these benefits has been limited until recently. This special issue presents recent findings on the ecosystem services and environmental benefits of agroforestry. The paper examines four major ecosystem services and environmental benefits: carbon sequestration, biodiversity conservation, soil enrichment, and air and water quality. Evidence shows that agroforestry, as part of a multifunctional working landscape, can be a viable land-use option that alleviates poverty and provides ecosystem services and environmental benefits. The introduction highlights that agroforestry is increasingly viewed as providing ecosystem services, environmental benefits, and economic commodities. The Millennium Ecosystem Assessment and the International Assessment of Agricultural Science and Technology for Development emphasize the multifunctional role of agroecosystems. There is also interest in providing financial benefits to landowners and farmers for land-use practices that maintain environmental services. Attempts have been made to quantify environmental benefits of agroforestry, but comprehensive reviews are rare. Reviews have mostly focused on a single ecosystem service. For example, Schroth et al. (2004) synthesized the role of agroforestry systems in conserving biodiversity in tropical landscapes. Schroth and Sinclair (2003) addressed soil fertility enhancement by agroforestry practices. Montagnini (2006) focused on carbon sequestration potential of agroforestry systems. The objective of this special issue is to bring together original research articles on various ecosystem services and environmental benefits from agroforestry practices worldwide. The integration of trees, agricultural crops, and/or animals into agroforestry systems can enhance soil fertility, reduce erosion, improve water quality, enhance biodiversity, increase aesthetics, and sequester carbon. These services occur over various spatial and temporal scales. Although the clean development mechanism offers promise for economic returns for carbon sequestration benefits, society's willingness to pay for other ecosystem services is yet to be fully explored. The major ecosystem services of agroforestry are classified into four categories: carbon sequestration, soil enrichment, biodiversity conservation, and air and water quality. Each is discussed in the following sections. Overall, the discussion cuts across the four major categories of ecosystem services identified by the Millennium Ecosystem Assessment.